This invention generally relates to intravascular catheters, particularly catheters for use in percutaneous transluminal coronary angioplasty (PCTA) or stent delivery.
In a typical PTCA procedure a dilatation balloon catheter is advanced over a guidewire to a desired location within the patient's coronary anatomy where the balloon of the dilatation catheter is properly positioned within the stenosis to be dilated. The balloon is then inflated to a predetermined size with radiopaque liquid at relatively high pressures (generally 8-18 atmospheres) to dilate the stenosed region of the diseased artery. One or more inflations may be needed to effectively dilate the stenosis. The catheter may then be withdrawn from the stenosis or advanced further into the patient's coronary anatomy to dilate additional stenoses.
The distal tip of an intravascular catheter may be constructed to have non-traumatic characteristics to minimize damage when passing through a body lumen. A typical non-traumatic tip is formed from a short tubular member made of relatively soft polymeric material which is secured to the distal tip of the tubular distal extremity of the catheter. However, this construction does not always eliminate injury to the luminal lining. For example, the leading edge of the distal skirt of the balloon which extends radially outward can cause intimal injury even though it may be somewhat tapered. Moreover, securing a distal tip made from softer material or otherwise designed to collapse so as to avoid intimal injury, complicates the manufacturing procedure and increases its costs.
What has been needed and heretofore unavailable is a simple, inexpensive method for forming a nontraumatic distal tip. The present invention satisfies this and other needs.